I finally got one!!! Philco Predicta

[Electronic M]

Your problem is in the horizontal oscillator. I assume you have changed all tubular paper dielectric caps, lytics and the couplates. Check resistors, and tube sockets (metal contacts break internally and go open), osc coil, solder joints, and B+ to the stage.

[cj_reha]

Originally Posted by Electronic M

Your problem is in the horizontal oscillator. I assume you have changed all tubular paper dielectric caps, lytics and the couplates. Check resistors, and tube sockets (metal contacts break internally and go open), osc coil, solder joints, and B+ to the stage.

All caps, resistors, tube sockets, and couplates have been changed. I haven't checked the coil, but I don't think that would be the problem as the set did have high voltage before I took the board out to recap/change couplates/etc. I think I'll make my own thread about troubleshooting as I'd rather not derail this one.

[Electronic M]

Originally Posted by cj_reha

All caps, resistors, tube sockets, and couplates have been changed. I haven't checked the coil, but I don't think that would be the problem as the set did have high voltage before I took the board out to recap/change couplates/etc. I think I'll make my own thread about troubleshooting as I'd rather not derail this one.

Good plan.
One thing I noticed on second read is that you measured the voltage on the output with the tube pulled...you want to remeasure with the tube installed....G1 only goes negative DC through grid-cathode rectification of the drive signal...pull the tube and you won't read negative there no matter what you do.... also the amount of G2 voltage will change depending on the fault...(assuming good G1 drive) high G2 means something in the flyback or later is shorted, low G2 means the damper or something else in the path from the damper B+ input to the h output plate is open (or in one of my sets it meant the width pot was open).

[judge]

Originally Posted by cj_reha

All caps, resistors, tube sockets, and couplates have been changed. I haven't checked the coil, but I don't think that would be the problem as the set did have high voltage before I took the board out to recap/change couplates/etc. I think I'll make my own thread about troubleshooting as I'd rather not derail this one.

I had the exact same problem. The cause was a bad replacement couplate. Do you still have the original you can try?